To remove trash and dirt from raw cotton many pneumatic systems have been devised in the past. One example of a relatively early system is shown in U.S. Pat. No. 1,265,908 which issued on May 14, 1918 to J. L. Hart. In this patent is described a pneumatic elevator and distributor for cotton gins wherein airborne cotton is first projected against a separator screen to remove dirt and then is moved through toothed rollers which cooperate to thoroughly clean the cotton, thoroughly separating the fibers, and tearing the matted cotton into a loose flocculent mass and the foreign matter, dirt and the like is discharged. The clean cotton is then distributed to any one of a series of gins.
Another pneumatic system of cleaning cotton is disclosed in U.S. Pat. No. 2,009,928 which issued on July 30, 1935, to N. B. Henry. In this patent, the cleaning is effected by directing the airborne cotton to cleaning rolls or by separation early by the air current that carries loose dirt away. This allows the operator to clean the cotton at will and avoid overcleaning or damage to green or damp cotton or long staple cotton.
In U.S. Pat. No. 3,163,472 which issued on Dec. 29, 1964, to A. Zeismar a pneumatic cotton cleaner is shown in which a series of deflectors and hanging rods are placed in the stream of air bearing cotton and as the cotton strikes the rods and deflectors, dirt and trash are dislodged and travel with the stream of air while the cotton falls to a collection bin.
U.S. Pat. No. 3,486,309 which issued on Dec. 30, 1969, to James Aubrey Wild shows an apparatus for pneumatically conveying bulk fiber waste from a plurality of textile machines, separating the fiber waste from the air by means of a filter separator unit and providing for momentarily reversing the air flow through the filter to clean the filters.
Still another apparatus using an air stream to collect textile fibers is described in U.S. Pat. No. 4,154,485 which issued on May 15, 1979, to K. G. Lytton et al and which discloses the use of an air stream bearing fibers to collect fibers on an isolating plate to form a web.
There is also a prior art fiber cleaning machine that directs a fiber laden stream of air onto a perforated screen by means of vertically extending plates that sweeps back and forth in front of the screen. The fibers strike and screen and drop down into a receiver while some of the trash contained in the fibers passes through the perforated screen for being separated from the fibers.
A general object of the present invention is to provide a method and apparatus which is an improvement over the above described prior art methods and apparatus for cleaning cotton.
Another object of the present invention is to provide a method and apparatus for cleaning cotton in which little or no damage is inflicted upon the cotton being cleaned.
Still another object of the present invention is to provide a method and apparatus in which the cotton undergoes a number of separating effects in a relatively uncomplicated series of steps.
Many other objects and advantages will become clear from the reading of the following description of the invention.